English

Edge coloring graphs with large minimum degree

Combinatorics 2021-07-20 v2

Abstract

Let GG be a simple graph with maximum degree Δ(G)\Delta(G). A subgraph HH of GG is overfull if E(H)>Δ(G)V(H)/2|E(H)|>\Delta(G)\lfloor |V(H)|/2 \rfloor. Chetwynd and Hilton in 1985 conjectured that a graph GG with Δ(G)>V(G)/3\Delta(G)>|V(G)|/3 has chromatic index Δ(G)\Delta(G) if and only if GG contains no overfull subgraph. The 1-factorization conjecture is a special case of this overfull conjecture, which states that for even nn, every regular nn-vertex graph with degree at least about n/2n/2 has a 1-factorization and was confirmed for large graphs in 2014. Supporting the overfull conjecture as well as generalizing the 1-factorization conjecture in an asymptotic way, in this paper, we show that for any given 0<ε<10<\varepsilon <1, there exists a positive integer n0n_0 such that the following statement holds: if GG is a graph on 2nn02n\ge n_0 vertices with minimum degree at least (1+ε)n(1+\varepsilon)n, then GG has chromatic index Δ(G)\Delta(G) if and only if GG contains no overfull subgraph.

Keywords

Cite

@article{arxiv.2105.05286,
  title  = {Edge coloring graphs with large minimum degree},
  author = {Michael J. Plantholt and Songling Shan},
  journal= {arXiv preprint arXiv:2105.05286},
  year   = {2021}
}

Comments

Fixed some typos and revised Lemmas 2.7, 2.11, and 2.12. arXiv admin note: substantial text overlap with arXiv:2104.06253

R2 v1 2026-06-24T02:00:33.543Z